Engines fire animation for mobile app created in Unity
There is no way (as far as I know) to bring a Blender particle system into Unity. If you want to use your Blender fire, render out transparent png sequences from all the sides that will be seen in game. Then use planes with with the images in Unity. However, given your knowledge of Unity and Blender, I would recommend you import Unity's free ParticleSystem pack and go from there.